The long term objectives of this project are to define the mechanisms which control synthesis, storage, release, action and termination of action of neurotransmitters and to determine how drugs, genetic factors, or environmental conditions influence these control mechanisms. The major areas of investigation during the last year have been on 1) the control in animals of plasma levels of catecholamines and dopamine-beta-hydroxylase. The effects of anesthetic agents, stress, drugs such as amphetamine reserpine and vinblastine, and genetic hypertension have been studied. 2) In vitro studies of agents which influence release as changes in enzyme levels using guinea pig vas deferens or cultured superior cervical ganglia. 3) Determination of the effect of halogen substitution on the activity of sympathomimetic amines.